We don't have a set price to quote you here without seeing the door - hardware this age varies a lot in what's actually salvageable versus what needs replacing outright. What we can tell you is the shape of the decision: a maintenance visit that catches a worn hinge or a dry track is cheap compared to what happens when that same worn part takes out a cable or throws a panel off its track under spring tension.
Spotswood households run a median income around $101,388, a bit under the wider service area's $122,610, and that's relevant only in the sense that it usually makes more financial sense to service what's original than to replace a whole door assembly before it's actually failed. We'll tell you straight if a part's not worth fixing anymore - that's a different call than most maintenance visits, but it happens on doors this old.